From 94c0e75bc85ad2a034c501b6d3640b880b9c3bb7 Mon Sep 17 00:00:00 2001
From: popcornmix <popcornmix@gmail.com>
Date: Fri, 28 Oct 2016 15:36:43 +0100
Subject: [PATCH] vc_mem: Add vc_mem driver for querying firmware memory
 addresses
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Signed-off-by: popcornmix <popcornmix@gmail.com>

BCM270x: Move vc_mem

Make the vc_mem module available for ARCH_BCM2835 by moving it.

Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
---
 drivers/char/broadcom/Kconfig   |  12 +-
 drivers/char/broadcom/Makefile  |   1 +
 drivers/char/broadcom/vc_mem.c  | 422 ++++++++++++++++++++++++++++++++++++++++
 include/linux/broadcom/vc_mem.h |  35 ++++
 4 files changed, 469 insertions(+), 1 deletion(-)
 create mode 100644 drivers/char/broadcom/vc_mem.c
 create mode 100644 include/linux/broadcom/vc_mem.h

--- a/drivers/char/broadcom/Kconfig
+++ b/drivers/char/broadcom/Kconfig
@@ -7,9 +7,19 @@ menuconfig BRCM_CHAR_DRIVERS
 	help
 	  Broadcom's char drivers
 
+if BRCM_CHAR_DRIVERS
+
 config BCM_VC_CMA
 	bool "Videocore CMA"
-	depends on CMA && BRCM_CHAR_DRIVERS && BCM2708_VCHIQ
+	depends on CMA && BCM2708_VCHIQ
 	default n
         help
           Helper for videocore CMA access.
+
+config BCM2708_VCMEM
+	bool "Videocore Memory"
+        default y
+        help
+          Helper for videocore memory access and total size allocation.
+
+endif
--- a/drivers/char/broadcom/Makefile
+++ b/drivers/char/broadcom/Makefile
@@ -1 +1,2 @@
 obj-$(CONFIG_BCM_VC_CMA)	+= vc_cma/
+obj-$(CONFIG_BCM2708_VCMEM)	+= vc_mem.o
--- /dev/null
+++ b/drivers/char/broadcom/vc_mem.c
@@ -0,0 +1,422 @@
+/*****************************************************************************
+* Copyright 2010 - 2011 Broadcom Corporation.  All rights reserved.
+*
+* Unless you and Broadcom execute a separate written software license
+* agreement governing use of this software, this software is licensed to you
+* under the terms of the GNU General Public License version 2, available at
+* http://www.broadcom.com/licenses/GPLv2.php (the "GPL").
+*
+* Notwithstanding the above, under no circumstances may you combine this
+* software in any way with any other Broadcom software provided under a
+* license other than the GPL, without Broadcom's express prior written
+* consent.
+*****************************************************************************/
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/fs.h>
+#include <linux/device.h>
+#include <linux/cdev.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/debugfs.h>
+#include <asm/uaccess.h>
+#include <linux/dma-mapping.h>
+#include <linux/broadcom/vc_mem.h>
+
+#define DRIVER_NAME  "vc-mem"
+
+// Device (/dev) related variables
+static dev_t vc_mem_devnum = 0;
+static struct class *vc_mem_class = NULL;
+static struct cdev vc_mem_cdev;
+static int vc_mem_inited = 0;
+
+#ifdef CONFIG_DEBUG_FS
+static struct dentry *vc_mem_debugfs_entry;
+#endif
+
+/*
+ * Videocore memory addresses and size
+ *
+ * Drivers that wish to know the videocore memory addresses and sizes should
+ * use these variables instead of the MM_IO_BASE and MM_ADDR_IO defines in
+ * headers. This allows the other drivers to not be tied down to a a certain
+ * address/size at compile time.
+ *
+ * In the future, the goal is to have the videocore memory virtual address and
+ * size be calculated at boot time rather than at compile time. The decision of
+ * where the videocore memory resides and its size would be in the hands of the
+ * bootloader (and/or kernel). When that happens, the values of these variables
+ * would be calculated and assigned in the init function.
+ */
+// in the 2835 VC in mapped above ARM, but ARM has full access to VC space
+unsigned long mm_vc_mem_phys_addr = 0x00000000;
+unsigned int mm_vc_mem_size = 0;
+unsigned int mm_vc_mem_base = 0;
+
+EXPORT_SYMBOL(mm_vc_mem_phys_addr);
+EXPORT_SYMBOL(mm_vc_mem_size);
+EXPORT_SYMBOL(mm_vc_mem_base);
+
+static uint phys_addr = 0;
+static uint mem_size = 0;
+static uint mem_base = 0;
+
+
+/****************************************************************************
+*
+*   vc_mem_open
+*
+***************************************************************************/
+
+static int
+vc_mem_open(struct inode *inode, struct file *file)
+{
+	(void) inode;
+	(void) file;
+
+	pr_debug("%s: called file = 0x%p\n", __func__, file);
+
+	return 0;
+}
+
+/****************************************************************************
+*
+*   vc_mem_release
+*
+***************************************************************************/
+
+static int
+vc_mem_release(struct inode *inode, struct file *file)
+{
+	(void) inode;
+	(void) file;
+
+	pr_debug("%s: called file = 0x%p\n", __func__, file);
+
+	return 0;
+}
+
+/****************************************************************************
+*
+*   vc_mem_get_size
+*
+***************************************************************************/
+
+static void
+vc_mem_get_size(void)
+{
+}
+
+/****************************************************************************
+*
+*   vc_mem_get_base
+*
+***************************************************************************/
+
+static void
+vc_mem_get_base(void)
+{
+}
+
+/****************************************************************************
+*
+*   vc_mem_get_current_size
+*
+***************************************************************************/
+
+int
+vc_mem_get_current_size(void)
+{
+	return mm_vc_mem_size;
+}
+
+EXPORT_SYMBOL_GPL(vc_mem_get_current_size);
+
+/****************************************************************************
+*
+*   vc_mem_ioctl
+*
+***************************************************************************/
+
+static long
+vc_mem_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	int rc = 0;
+
+	(void) cmd;
+	(void) arg;
+
+	pr_debug("%s: called file = 0x%p\n", __func__, file);
+
+	switch (cmd) {
+	case VC_MEM_IOC_MEM_PHYS_ADDR:
+		{
+			pr_debug("%s: VC_MEM_IOC_MEM_PHYS_ADDR=0x%p\n",
+				__func__, (void *) mm_vc_mem_phys_addr);
+
+			if (copy_to_user((void *) arg, &mm_vc_mem_phys_addr,
+					 sizeof (mm_vc_mem_phys_addr)) != 0) {
+				rc = -EFAULT;
+			}
+			break;
+		}
+	case VC_MEM_IOC_MEM_SIZE:
+		{
+			// Get the videocore memory size first
+			vc_mem_get_size();
+
+			pr_debug("%s: VC_MEM_IOC_MEM_SIZE=%u\n", __func__,
+				mm_vc_mem_size);
+
+			if (copy_to_user((void *) arg, &mm_vc_mem_size,
+					 sizeof (mm_vc_mem_size)) != 0) {
+				rc = -EFAULT;
+			}
+			break;
+		}
+	case VC_MEM_IOC_MEM_BASE:
+		{
+			// Get the videocore memory base
+			vc_mem_get_base();
+
+			pr_debug("%s: VC_MEM_IOC_MEM_BASE=%u\n", __func__,
+				mm_vc_mem_base);
+
+			if (copy_to_user((void *) arg, &mm_vc_mem_base,
+					 sizeof (mm_vc_mem_base)) != 0) {
+				rc = -EFAULT;
+			}
+			break;
+		}
+	case VC_MEM_IOC_MEM_LOAD:
+		{
+			// Get the videocore memory base
+			vc_mem_get_base();
+
+			pr_debug("%s: VC_MEM_IOC_MEM_LOAD=%u\n", __func__,
+				mm_vc_mem_base);
+
+			if (copy_to_user((void *) arg, &mm_vc_mem_base,
+					 sizeof (mm_vc_mem_base)) != 0) {
+				rc = -EFAULT;
+			}
+			break;
+		}
+	default:
+		{
+			return -ENOTTY;
+		}
+	}
+	pr_debug("%s: file = 0x%p returning %d\n", __func__, file, rc);
+
+	return rc;
+}
+
+/****************************************************************************
+*
+*   vc_mem_mmap
+*
+***************************************************************************/
+
+static int
+vc_mem_mmap(struct file *filp, struct vm_area_struct *vma)
+{
+	int rc = 0;
+	unsigned long length = vma->vm_end - vma->vm_start;
+	unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
+
+	pr_debug("%s: vm_start = 0x%08lx vm_end = 0x%08lx vm_pgoff = 0x%08lx\n",
+		__func__, (long) vma->vm_start, (long) vma->vm_end,
+		(long) vma->vm_pgoff);
+
+	if (offset + length > mm_vc_mem_size) {
+		pr_err("%s: length %ld is too big\n", __func__, length);
+		return -EINVAL;
+	}
+	// Do not cache the memory map
+	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+
+	rc = remap_pfn_range(vma, vma->vm_start,
+			     (mm_vc_mem_phys_addr >> PAGE_SHIFT) +
+			     vma->vm_pgoff, length, vma->vm_page_prot);
+	if (rc != 0) {
+		pr_err("%s: remap_pfn_range failed (rc=%d)\n", __func__, rc);
+	}
+
+	return rc;
+}
+
+/****************************************************************************
+*
+*   File Operations for the driver.
+*
+***************************************************************************/
+
+static const struct file_operations vc_mem_fops = {
+	.owner = THIS_MODULE,
+	.open = vc_mem_open,
+	.release = vc_mem_release,
+	.unlocked_ioctl = vc_mem_ioctl,
+	.mmap = vc_mem_mmap,
+};
+
+#ifdef CONFIG_DEBUG_FS
+static void vc_mem_debugfs_deinit(void)
+{
+	debugfs_remove_recursive(vc_mem_debugfs_entry);
+	vc_mem_debugfs_entry = NULL;
+}
+
+
+static int vc_mem_debugfs_init(
+	struct device *dev)
+{
+	vc_mem_debugfs_entry = debugfs_create_dir(DRIVER_NAME, NULL);
+	if (!vc_mem_debugfs_entry) {
+		dev_warn(dev, "could not create debugfs entry\n");
+		return -EFAULT;
+	}
+
+	if (!debugfs_create_x32("vc_mem_phys_addr",
+				0444,
+				vc_mem_debugfs_entry,
+				(u32 *)&mm_vc_mem_phys_addr)) {
+		dev_warn(dev, "%s:could not create vc_mem_phys entry\n",
+			__func__);
+		goto fail;
+	}
+
+	if (!debugfs_create_x32("vc_mem_size",
+				0444,
+				vc_mem_debugfs_entry,
+				(u32 *)&mm_vc_mem_size)) {
+		dev_warn(dev, "%s:could not create vc_mem_size entry\n",
+			__func__);
+		goto fail;
+	}
+
+	if (!debugfs_create_x32("vc_mem_base",
+				0444,
+				vc_mem_debugfs_entry,
+				(u32 *)&mm_vc_mem_base)) {
+		dev_warn(dev, "%s:could not create vc_mem_base entry\n",
+			 __func__);
+		goto fail;
+	}
+
+	return 0;
+
+fail:
+	vc_mem_debugfs_deinit();
+	return -EFAULT;
+}
+
+#endif /* CONFIG_DEBUG_FS */
+
+
+/****************************************************************************
+*
+*   vc_mem_init
+*
+***************************************************************************/
+
+static int __init
+vc_mem_init(void)
+{
+	int rc = -EFAULT;
+	struct device *dev;
+
+	pr_debug("%s: called\n", __func__);
+
+	mm_vc_mem_phys_addr = phys_addr;
+	mm_vc_mem_size = mem_size;
+	mm_vc_mem_base = mem_base;
+
+	vc_mem_get_size();
+
+	pr_info("vc-mem: phys_addr:0x%08lx mem_base=0x%08x mem_size:0x%08x(%u MiB)\n",
+		mm_vc_mem_phys_addr, mm_vc_mem_base, mm_vc_mem_size, mm_vc_mem_size / (1024 * 1024));
+
+	if ((rc = alloc_chrdev_region(&vc_mem_devnum, 0, 1, DRIVER_NAME)) < 0) {
+		pr_err("%s: alloc_chrdev_region failed (rc=%d)\n",
+		       __func__, rc);
+		goto out_err;
+	}
+
+	cdev_init(&vc_mem_cdev, &vc_mem_fops);
+	if ((rc = cdev_add(&vc_mem_cdev, vc_mem_devnum, 1)) != 0) {
+		pr_err("%s: cdev_add failed (rc=%d)\n", __func__, rc);
+		goto out_unregister;
+	}
+
+	vc_mem_class = class_create(THIS_MODULE, DRIVER_NAME);
+	if (IS_ERR(vc_mem_class)) {
+		rc = PTR_ERR(vc_mem_class);
+		pr_err("%s: class_create failed (rc=%d)\n", __func__, rc);
+		goto out_cdev_del;
+	}
+
+	dev = device_create(vc_mem_class, NULL, vc_mem_devnum, NULL,
+			    DRIVER_NAME);
+	if (IS_ERR(dev)) {
+		rc = PTR_ERR(dev);
+		pr_err("%s: device_create failed (rc=%d)\n", __func__, rc);
+		goto out_class_destroy;
+	}
+
+#ifdef CONFIG_DEBUG_FS
+	/* don't fail if the debug entries cannot be created */
+	vc_mem_debugfs_init(dev);
+#endif
+
+	vc_mem_inited = 1;
+	return 0;
+
+	device_destroy(vc_mem_class, vc_mem_devnum);
+
+      out_class_destroy:
+	class_destroy(vc_mem_class);
+	vc_mem_class = NULL;
+
+      out_cdev_del:
+	cdev_del(&vc_mem_cdev);
+
+      out_unregister:
+	unregister_chrdev_region(vc_mem_devnum, 1);
+
+      out_err:
+	return -1;
+}
+
+/****************************************************************************
+*
+*   vc_mem_exit
+*
+***************************************************************************/
+
+static void __exit
+vc_mem_exit(void)
+{
+	pr_debug("%s: called\n", __func__);
+
+	if (vc_mem_inited) {
+#if CONFIG_DEBUG_FS
+		vc_mem_debugfs_deinit();
+#endif
+		device_destroy(vc_mem_class, vc_mem_devnum);
+		class_destroy(vc_mem_class);
+		cdev_del(&vc_mem_cdev);
+		unregister_chrdev_region(vc_mem_devnum, 1);
+	}
+}
+
+module_init(vc_mem_init);
+module_exit(vc_mem_exit);
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Broadcom Corporation");
+
+module_param(phys_addr, uint, 0644);
+module_param(mem_size, uint, 0644);
+module_param(mem_base, uint, 0644);
--- /dev/null
+++ b/include/linux/broadcom/vc_mem.h
@@ -0,0 +1,35 @@
+/*****************************************************************************
+* Copyright 2010 - 2011 Broadcom Corporation.  All rights reserved.
+*
+* Unless you and Broadcom execute a separate written software license
+* agreement governing use of this software, this software is licensed to you
+* under the terms of the GNU General Public License version 2, available at
+* http://www.broadcom.com/licenses/GPLv2.php (the "GPL").
+*
+* Notwithstanding the above, under no circumstances may you combine this
+* software in any way with any other Broadcom software provided under a
+* license other than the GPL, without Broadcom's express prior written
+* consent.
+*****************************************************************************/
+
+#ifndef _VC_MEM_H
+#define _VC_MEM_H
+
+#include <linux/ioctl.h>
+
+#define VC_MEM_IOC_MAGIC  'v'
+
+#define VC_MEM_IOC_MEM_PHYS_ADDR    _IOR( VC_MEM_IOC_MAGIC, 0, unsigned long )
+#define VC_MEM_IOC_MEM_SIZE         _IOR( VC_MEM_IOC_MAGIC, 1, unsigned int )
+#define VC_MEM_IOC_MEM_BASE         _IOR( VC_MEM_IOC_MAGIC, 2, unsigned int )
+#define VC_MEM_IOC_MEM_LOAD         _IOR( VC_MEM_IOC_MAGIC, 3, unsigned int )
+
+#if defined( __KERNEL__ )
+#define VC_MEM_TO_ARM_ADDR_MASK 0x3FFFFFFF
+
+extern unsigned long mm_vc_mem_phys_addr;
+extern unsigned int  mm_vc_mem_size;
+extern int vc_mem_get_current_size( void );
+#endif
+
+#endif  /* _VC_MEM_H */
